Received-SPF: pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Miles Chen <miles.chen@mediatek.com>
To:     <jason@zx2c4.com>
CC:     <ardb@kernel.org>, <davem@davemloft.net>,
        <gregkh@linuxfoundation.org>, <herbert@gondor.apana.org.au>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-crypto@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-mediatek@lists.infradead.org>, <matthias.bgg@gmail.com>,
        <miles.chen@mediatek.com>
Subject: Re: [PATCH] lib/crypto: blake2s: fix a CFI failure
Date:   Wed, 19 Jan 2022 17:24:40 +0800
Message-ID: <20220119092440.4045-1-miles.chen@mediatek.com>
In-Reply-To: <CAHmME9pv4WWATjdqZgwrtHDmq3sX4ABfB9PoNT9Z4tSEduR2Lw@mail.gmail.com>
References: <CAHmME9pv4WWATjdqZgwrtHDmq3sX4ABfB9PoNT9Z4tSEduR2Lw@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

hi,

>Thanks for the patch. Could you let me know which architecture and
>compiler this was broken on? If I had to guess, I'd wager arm32, and
>you hit this by enabling optimized blake2s?

Actually, I am merging android-common tree and test our device.
I use arm64 and clang-r437112b.

I'm not sure which option is the right one, grep 'BLAKE' .config shows:

CONFIG_CRYPTO_BLAKE2B=y
# CONFIG_CRYPTO_BLAKE2S is not set
# CONFIG_CRYPTO_LIB_BLAKE2S_GENERIC=y

and... I found that my patch breaks arm32 build, sorry for that.

>If so, I'm not sure the problem is with weak symbols. Why should CFI
>break weak symbols? Rather, perhaps the issue is that the function is
>defined in blake2s-core.S? Are there some CFI macros we need for that
>definition?